1. Field of the Invention
The present invention relates to a graphics system for providing improved pointer selection accuracy.
2. Description of Prior Art
When selecting an object with a mouse or other pointing device users commonly nudge the pointer while depressing the selection button. This can cause a failure to selection the intended object, or alternatively, inadvertent selection of an object adjacent to the intended object. For example, in FIG. 1, a user who positions a pointer on Object X may inadvertently cause the pointer to move onto Object Y just before clicking the selection button.
This can be a particular problem for partially disabled users or users not accustomed to mice, when selecting small or thin objects. It can also arise in a cluttered environment, or in the presence of unexpectedly selectable objects. A similar problem arises when selecting a moving target.
The present invention relates to a graphics system which remembers the object which the pointer has been pointing at in the recent past.
In a preferred embodiment, an object may be selected even if the pointer is no longer pointing at that object when the selection event is registered. In this case two threshold intervals are used, a pause interval (pi), and a nudge interval (ni). The pause interval prevents incorrect selection, and the nudge interval permits selection even if the pointer is nudged during selection.
In an alternative embodiment, the selection is only successful if the pointer has consistently been pointing at the same object for more than the threshold pause interval (pi) when the selection (e.g., mouse down) event is registered. This prevents selection of the incorrect adjacent object, but does not assist selection of the correct object. Thus, the second mode is a special case of the first mode, with ni=0.
Typical values are pi=0.3 seconds and ni=0.1 second for an uncertain user, pi=0.15 seconds and ni=0.05 seconds for a more experienced user. It will be seen that ni less than pi as otherwise there may be a possibility of an ambiguity in the object to be selected.
In yet another embodiment of the present invention, a graphics system for a graphical user interface (GUI) is disclosed in which screen objects are displayed. The GUI includes targeting means for determining a screen object targeted by the pointer, and selection means for reading a pointer selection and for selecting a screen object.
The graphics system can be characterized by a selection means including means for selecting a screen object which has been continuously targeted for a predetermined time (pi).
Preferably, the targeting means includes means for recording a time at which a screen object becomes targeted. The targeting means also includes means for reading a pointer position before determining which object is targeted.
According to one embodiment of the present invention, the selection means includes means for selecting a screen object which has been continuously targeted for the predetermined time (pi) and for a predetermined time (ni) after it ceases to be targeted. In one embodiment, the predetermined times ni and pi are stored within the graphics system.
According to another embodiment of the present invention, a control panel is associated with the graphics system. The control panel is responsive to user interaction and updating the predetermined times ni and pi according to the interaction. The predetermined time pi is greater than the predetermined time ni.
According to one embodiment of the present invention, the graphics system is embodied in an operating system. Alternatively, the graphics system is embodied in an application wherein the application is one of a general purpose application or a dedicated application.
Further, in another embodiment of the present invention, a computer program product including computer program code stored on a computer readable storage medium for, when executed on a computing device, controls the selection of screen objects, the program code including the graphical system.
In an alternative embodiment of the present invention, a graphics system for a graphical user interface is presented. In this embodiment screen objects are displayed, and a method for selecting a screen object includes determining the screen object targeted by the pointer, and selecting the screen object which has been continuously targeted for a predetermined time (pi), and is responsive to a pointer selection.